Fastening buckle for safety belts or the like



P. o. WEMAN 3,348,274

FASTENING BUCKLE FOR SAFETY BELTS OR THE LIKE Oct. 24, 1967 Z'Sheets-Sheet 1 Filed June 6, 1966 Inventor.-

PER OLAF WEMAN A t to r ne FASTENING BUCKLE FOR SAFETY BELTS OR THE LIKE Filed June 6, 1966 P. O. WEMAN Oct- 24, 1967 2 Sheets-Sheet 2 lnvemor:

PER OLAF WEMAN Mfiu Kt orney United States Patent 1 O 3,348,274 FASTENING BUCKLE FOR SAFETY BELTS OR THE LIKE Per Olaf Weman, Hamburg, Germany, assignor to Sigmatex A.G., Basel, Switzerland Filed June 6, 1966, Ser. No. 555,571 Claims priority, application Germany, Oct. 30, 1965, S 100,293 7 Claims. (Cl. 24-233) The present invention relates to a buckle for fastening safety belts or the like to fixed brackets.

The primary objects of this invention are to provide a fastening buckle that: gives a secure attachment of a belt to a bracket, can be opened and closed with ease with one hand, is simple in its construction and assembly, and is easy to manipulate.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with an embodiment and described therein and shown in the accompanying drawings, wherein like reference numerals designate like parts and wherein:

FIGURE 1 is a plan view of a fastening buckle of the invention, along with bracket and belt, in the locked position.

FIGURE 2 is a plan view of a fastening buckle of the invention, along with bracket and belt, in the opened position.

The present invention creates a belt buckle having a low friction between a locking hook and a bracket holding recess, so that only a very small force is required to open the buckle.

According to the invention, the objects are accomplished by mounting a locking hook pivotably at one end on a displaceable buckle plate, and by having this locking the buckle plate in the housing to a magnitude wherein the locking hook is pivoted from its locking position into the release position, the invention provides, in a further development, that the buckle plate, as well as the buckle housing, are provided with stops which limit the displacement of the buckle plate within the housing in both directions of displacement.

With respect to a spring required for automatically returning the buckle plate from the release position into the locking position, and for holding the same therein, the invention provides that the spring abuts, on the one hand, on the displaceable buckle plate and, on the other hand, on the locking hook mounted to the buckle plate. Thereby, one spring is sufficient to also hold the locking hook in its locking position, thus maintaining a force directed against the opening of the hook.

The locking hook, in its locking position, contacts, with an abutment surface of its inner edge, the bracket laterally from andapproximately parallel to the longitudinal center line of the belt buckle. Consequently, the locking I hook need not absorb the major forces which occur, for

example, during an accident, in the form of tractive forces in the belt. These forces are transmitted to the bracket by the buckle plate. The locking hook serves only as a safety device against opening of the buckle because of the occurrence of small forces lateral to the longitudinal axis hook engage, with its free end, a supporting rim of a buckle housing, under the pressure of a spring. The swivel joint of the locking hook is carried along when the buckle plate is displaced relative to the housing. The free end of the locking book can roll along the supporting rim in such a manner that the hook moves from its locking position into its release position. Thus frictional forces which would arise, for example, from a sliding movement of the free end of the locking hook, do not have to be overcome. Moreover, in this arrangement the locking hook and the inner wall of a hook-shaped cutout of the buckle plate engaging the bracket can be constructed such that the friction between the bracket and the locking hook is substantially smaller than in a case wherein almost the entire tractive force effective upon a belt is transmitted by a release pawl to the bracket. The solution according the the invention makes it possible to provide an arrangement wherein the tractive force is transmitted by the buckle plate to the bracket, while the release member or the locking hook forms only an additional lateral guide and bears only minor stresses. This particular fact is an advantage since previously, when the buckle was to be opened, the bracket was under tight contact against the locking hook, whereby the pivoting of the hook required for the opening operation was made difficult.

The above-mentioned advantages of the invention are likewise apparent when, in order to strengthen the lock and for safety reasons, the buckle plate has two locking hooks, one on each of its sides; in a further development of the invention, it proves to be suitable for simplicity of construction to fasten both locking hooks to the buckle plate by a common pin.

In order to limit the possible path of displacement of of the buckle or to the longitudinal direction of the belt, such forces arising, for example, due to a hooked recess extending obliquely to the longitudinal axis of the buckle. This arrangement furthermore makes it possible to open the buckle without effort, since there are no substantial frictional forces between the bracket and the locking hook, nor between the locking hook and the housing, nor between the locking hook and the buckle plate, when the buckle is opened. These above advantages are advanced by a further feature of the invention wherein the abutment surface of the locking hook in the locking position is located approximately on the perpendicular drawn from the pivot of the locking hook to the longitudinal center line of the buckle.

The belt buckle illustrated in the drawing has a housing 1 made, for example, of plastic. The longitudinal central axis of the buckle is designated by I-I. This housing 1 is provided at its upper side and under side with slotshaped openings 2 and 3 respectively. In the housing 1, a buckle plate 4 is mounted longitudinally displaceably in the direction of'the axis II. The buckle plate 4 is provided with a cutout 5. The belt 6 is fastened on the upper edge 27 of this cutout. The buckle plate 4 has guide portions 7 and 8 on both sides, the lower stop edges of which, designated by 9 and 10, cooperate with stops 11 and 12 of the housing 1 for the purpose of limiting the displacement of the buckle plate 4 within the housing 1 in the downward direction.

At its lower edge, the buckle plate 4 is provided with a hook-shaped recess 13 serving for the reception and fastening of a bracket 14 which is mounted in a stationary manner, for example, in an automobile.

Laterally from the hook-shaped cutout 13, the displaceable buckle plate 4 has a pin 15 upon which there are rotatably mounted two identical locking hooks 16 and 17. These two locking hooks 16 and 17 are positioned respectively on one of the two sides of the buckle plate 4, so that, in a plan view, only one of them is visible.

The two locking hooks 16, 17 are provided with identical cutouts 18 made sufiiciently wide to encompass the section of the bracket 14.

At their respective front ends, the locking hooks 16, 17 each have a tongue 19 with an arcuate contact area 20 with which they engage a supporting rim 21 of the buckle housing 1. At their upper sides, the locking hooks 16 and 17 are provided with a projection 22 upon which a spring 23 presses, this spring, at its other end, abutting upon the buckle plate 4. The following mode of operation results from this construction. When the belt 6 and the buckle are connected with a bracket 14, and the buckle is in the locking position according to FIGURE 1, then, upon a sudden pull on the belt strap 6, for example, during an accident, the pull is transmitted by the wall 24 of the recess 13 of the buckle plate 4, in the form of a pressure force, onto the bracket 14. A substantially smaller proportion of forces is transmitted to the abutment wall 25 of the locking hooks 16 and 17. There is no danger of the buckle opening, since these forces, which are effective laterally to the line I-I, are absorbed by the pin 15 so that, in any event, the buckle cannot enter into its open position. Any arising torques arising around pin 15 act to force the hooks 16 and 17 against the bracket 14.

When the buckle is to be opened in order to release the belt from its anchoring, a pull must be exerted upon the housing 1 in the direction of the arrow B. The locking hooks 16 and 17 are carried along since they contact the supporting rim 21 of the housing 1 and are pressed about the pin 15 in a counterclockwise direction.

If the housing 1 is lifted to such an extent that the lower stop edges 9 and 10 at the edge of the buckle plate 4 contact the stops 11 and 12 of the housing 1, the locking hooks 16 and 17 are by then pivoted into the open- 7 ing position where the cutout 13 in the buckle plate 4 is free, and the entire buckle can be pulled off the bracket 14.

For fastening the belt buckle to the bracket 14, it is not necessary to displace the housing 1 relatively to the buckle plate 4. Rather, it is suflicient to press the buckle, which is normally in its locking position, against the bracket 14 in such a manner that the latter pushes the locking hooks 16 and 17, against the force of the spring 23, into the interior of the housing to such an extent that the cutout 13 is free, so that the bracket slides up to the end of this cutout, the locking pawls 16 and 17 snapping back into their locking position shown in FIGURE 1 under the force of the spring 23. A stop 26 at the inner wall of the housing 1 which engages the cutout 5 of the buckle plate 4.has the purpose, in this push-in step, of preventing the buckle plate 4 from being pushed out of the housing 1 in the upward direction.

While other proportions within limits are feasible, the proportions shown in the drawings are to scale in a preferred embodiment of the invention.

It should be understood, of course, that the foregoing disclosure relates to only preferred embodiments of the invention and that it is intended to cover all changes and modifications of the examples of the invention herein chosen for the purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention set forth in the appended claims.

I claim:

1. A fastening buckle for connecting safety belts and the like to brackets, comprising a buckle plate having a hook-shaped recess at one end to receive a bracket and a belt attaching means at the opposite end; a locking-hook means pivotably mounted on said plate to lock a bracket in said recess; a housing mounted around said locking hook means on said plate and movable relative to the two fixed ends of said plate; said housing having a supporting rim in contact with a free end of said lockinghook means; and a spring means to hold the free end continually in contact with said rim.

2. A buckle as in claim 1, further comprising a second locking-hook means pivotably mounted on the side of said plate opposite to that on which the first is mounted.

3. A buckle as in claim 2, both locking-hook means pivoted about a common pin.

4. A buckle as in claim 1, further comprising stop means in said housing and on said plate to limit the relative movement between housing and plate.

5. A buckle as in claim 1, there being a recess in the buckle plate, said spring means mounted in said recess, one end of said spring means pushing on said plate and the other end pushing on the free end of said lockinghook means.

6. A buckle as in claim 1, said locking-hook means having a bracket abutting surface situated in the closed position laterally from and approximately parallel to the longitudinal center line of the buckle.

7. A buckle as in claim 6, said bracket abutting surface situated approximately in the closed position on the perpendicular drawn from the pivot of said locking-hook means to the longitudinal center line of the buckle.

References Cited UNITED STATES PATENTS 3,110,072 11/1963 Carreberg 24-239 3,217,373 11/1965 Bohlin 24-239 FOREIGN PATENTS 711,852 6/1965 Canada.

WILLIAM FELDMAN, Primary Eadaminer.

DONALD A. GRIFFIN, Examiner. 

1. A FASTENING BUCKLE FOR CONNECTING SAFETY BELTS AND THE LIKE TO BRACKETS, COMPRISING A BUCKLE PLAT HAVING A HOOK-SHAPED RECESS AT ONE END TO RECEIVE A BRACKET AND A BELT ATTACHING MEANS AT THE OPPOSITE END; A LOCKING-HOOK MEANS PIVOTABLY MOUNTED ON SAID PLATE TO LOCK A BRACKET IN SAID RECESS; A HOUSING MOUNTED AROUND SAID LOCKING HOOK MEANS ON SAID PLATE MOVABLE RELATIVE TO THE TWO FIXED ENDS OF SAID PLATE; SAID HOUSING HAVING A SUP- 